1. Field of the Invention
The present invention generally relates to a metal structure for a light-emitting diode. Particularly, the present invention relates to a metal structure for a light-emitting diode having thermal dissipation effect and high extraction efficiency.
2. Description of the Prior Art
Light-emitting diodes are characterized in low energy consumption, long lifetime and have been extensively employed in building decorations, indoor illumination, commercial spaces, mass transportation, automobiles, computers, and cell phones. Generally speaking, for a 5630 package (i.e. 5.6 mm in length and 3.0 mm in width), though the thermal dissipation design is employed, the light extraction efficiency and the thermal dissipation design are obviously insufficient as the customer demand increases. The main issue of the light-emitting diode manufacture process is related to the light extraction efficiency and the thermal dissipation.
As shown in FIG. 1, the traditional light-emitting diode includes a bowl 30, a resin encapsulation body 50, and a light-emitting diode chip 70. The bowl 30 is disposed with the electrode 10, wherein the electrical connection is formed between the light-emitting diode chip 70 and the electrode 10. Light in the resin encapsulation body 50 of such a light-emitting diode is total internal reflection due to the difference in refraction index between the resin encapsulation body 50 and the external medium. After several times of reflection, energy is substantially absorbed by the bowl 30, thus causing the poor extraction efficiency. If a high polymer material, such as polyphthalamide (PPA), is disposed as a reflector on the inner surface of the bowl 30, the high polymer material would be apt to blackening and lead to light attenuation.
In other traditional approaches, if a metal reflector is disposed on the electrode, the bottom of the reflector requires an additional insulating structure to isolate the electrode, which complicates the manufacturing process thereof. Besides, the light-emitting diode without any thermal dissipation design in the package process would lead to an abnormal thermal dissipation, resulting in shorter lifetime of the light-emitting diode and light attenuation.